Heating and illuminating gas and method of making same



lNvENToRs ATTORNEYS Dec. 15, w36. WH. HAMPTON Er AL,

HEATING AND I'LLUMINATING GAS A ND METHoDoF KING SAME Ifiled Dec. 17, `1929 patented Dee. 1 5, 1936 UNITED STATES PATENT ori-ics HEATING AND ILLUMNATING GAS AND METHOD IOI" MAKING SAME William H. Hampton and John T. Rutherford', Berkeley, Calif., assignors to Standard Oil Company of California, San Francisco, Calif., a corporation of Delaware Application December 11, 1929, seriailNor 414,817

16 Claims.

not, of themselves, possess suiiicient odor to warn of their presence when they escape from the containers, piping, or fixtures wherein they are used 3 and a danger results in such instances due to the l explosive or toxic hazards created.

Natural gas, such for example as is obtained from natural gas wells and oil wells, does not possess a marked color. Consequently, when natural gas is used for heating, cooking or illumination in the home or in industrial plants, it is possible for asphyxiative or explosible quantities of the gas to accumulate unnoticed by the persons in contact with the gas.

Various odorants have been used heretofore to give the gas a characteristic odor which will give proper warning of danger. So .far as is known, all odorants heretofore employed have one or more objections. Some odorants are not distinctive and do not rouse the victim to action, orv the odorant, while distinctive, may be so offensive that users of the gas containing the odorant object to the odor. With some odorants excessive quantities of odorant are required.

The heating andA illuminating gas which is the subject of the present invention contains an odorant which has a distinct and penetrative odor. It is easily and unmistakably detectable before explosive mixtures or asphyxiative concentrations are reached. In addition merely of warning one of its presence it is suiliciently distinctive to rouse one to action. On the other hand it is not so obnoxious as to be objectionable to the customer.

When used in proper proportions the odorantv not impart undesirable properties to the fuel. Another object is to disclose and provide a method of producing a hydrocarbon gas which is capable of signalling its presence through the olfactory organs, even when present in low concentra- 5 tions, said gas being substantially odorless when burned.

`In this novel odorant there exists a series of volatile organic compounds. While most of these are believed to be principally organic suldes of the saturated ring heterocyclic type; containing three or more carbon atoms and sulfur as a 'hetero-atom, other organic `sulfur compounds such as aliphatic sulfldes, disuldes, polysuldes, mercaptans and thiophene homologues may be 15 incidentally present. There may also be present Inon-sulfur bodies. The saturated ring heterocyclic sulfides referred to are to be distinguished 4 from hydrosuliides or mercaptans (R-vS-H type). and from thiophenes which contain only four carbon atoms and are unsaturated. They have an odor which is distinct'from the odor of common mercaptans and from thiophenes, and principally comprise the effective odorizing constituents of the odorant oil herein described. Their odor is readily distinguished from the mild odor of the thiophenes, it being remembered that disulfldes have practically no odor and are of no importance in the performance of this invention. Some of these sulfur compounds are of the type such that they have a distinctive, intense and penetrative odor so that minute quantities can be used to impartthe necessary o dor tothe gas.-

`The quantities required are so small that the sulfur content of the gas is not appreciably increased over that which ordinarily exists in the gas.

The odorant embraced by this invention is distinctly perceptible by most people when it exists at a concentration of 0.25 part per million. In other words` when the product is used in the proportion ofthree gallons per million cubic feet of gas, it will produce a distinct odor when a sufcient quantity of the gas is admitted into the -room so that 0.5 per cent of the odorized gas is present in the air thereof. These sulfur compounds occur in many petroleum oils so that when such oils are treated with suitable reagents, such as sulfuric acid, they will be found to exist in the resulting acid sludge. This sludge may be disstilled or it may rst be subjected to hydrolysis and then distilled to produce a volatile component in which these sulfur compounds will be found.

The sulfuric acid may react on certain of the compounds normally existing in oil so as to change'them in molecular structure Aduring the of the odorant is shown by the following inspections on ve different odorants, any one of which or any combination of which will produce a suitable odorant.

. f Mix- Mixi ture of ture of st ht cracked cracked Cracked rmg ggg' gs' run Keroohne ohne Type of sludge gli.; gasseno kero: kero:

oline sono, sono liquid liquid petropetrolatum latum Odorant:

Gravity/,url 30.8 26.6 27.0 A25. 7 43.0 Percent suliur. 9. 18% 15. 48% 2. 13% 4. 68% 5. 09% Color Saybolt..` Belovg Below Belovg Below) Belovg rmsuclosedtag. Below a0F.+-1o0F.+- 124 F. Below 80 F 80 F A s T. M. Dist 100F 25z1r 3003 3103 112 20 284 a Pi d 5017"-. 349 335 372 40s 302 e 4,90 386 430 46a 301 End poinc B 495 432 453 524 390 The color of the odorant ranges from .water white to yellow or amber, but is usually yellow.

While the properties of the odorants listed above vary considerably it is possible to control the process of productionso asl to obtain a uniform odorant having any desired properties. We find that the sulfur content of our odorant may range from 2% to 30%, by weight, of the odorant, but usually does not exceed 18%.

The boiling 'point range of the odorant may` range between 100 F. and 600-F. The selection 'of a suitable boiling point range for any specic odorant will depend upon two factors.; rst, the amount of odorant required to impart a ,noticeable odor to the gas; and second, the temperature and pressure under which the gas is stored and distributed. It is essential that odorant should evaporate completely and the distillation of the sludge should be carried out with this in mind. Since gas is distributed under varying pressures and temperatures an odorant must be selected which will evaporate under lthe highest pressurev and lowest temperature existing in the distrib- .uting system. We find, for example that where gasis distributed at pressures as high as 250 pounds per square inch and atv temperatures as low as F. the odorant should have an end point not overilf20 F. and should yield '10% by distillation at 340 F. With lower pressures and l higher temperatures, odorants having higher boiling points can be used. Likewise, for higher vpressures and lower temperatures the odorant should have lower boiling points.

The concentration of odorant required in the gas to produce the distinct and penetrating odor desired is an important factor in the selection of an odorant. An odorant made from sludge resulting from the acid treatment of raw cracked gasoline or straight run gasoline is particularly desirable on account, of the low concentrations required to produce a satisfactory odor.

It should be noted, however, that the method of treating may also influence the character of the odorant. Tlius two sludges produced from 'the same oil stock but withdiierent acid treatments such as with various kinds, amounts or strengths of acid at different temperatures will have different physical properties. The lighter petroleum oils such as naphthas, gasoline, and kerosene are: the best source of volatile organic sulfur compounds although small amountsof volatile organic sulfur compounds can be obtained from higher boiling point petroleum oils.

The foregoing description has defined the physical and chemical characteristics of the odorant insofar as this can be done and has set forth briefly the source from which the odorant is obtained. The following descriptions relate to different methods of obtaining the odorant from the sludge and are' given to enable those skilled in thev art toproduce the odorant.

Petroleumfoils are usually treated with acids for removal of impurities. Among the impurities which it is desirabletoremove are the organic sulfur compounds. These are commonly removed by the use of such acids as sulfuric acid, includ'- l ing fuming sulfuric acid, sulfuric anhydride (S03), or sulfur dioxide. The organic sulfur compoundsare composed mainly of organic suldes, disuldes, polysulfides, mercaptans and thiophene homologues.

l During the acid treatment these organic sulfur compounds are dissolved inor combined with the acid. In either event they will be found in the sludge resulting from the acid treatment.

The odorant which is the subject of this invention can-be obtained, containing these organic suldes, by distilling the sludge by any of the Well-known methods, either at atmospheric or superatmospheric pressure or with vacuum, and condensing the volatilized constituentsresulting from the distillation. The condensate formed is an oily compound. A part of the acid component of the sludge is distilled over with the sulfur compounds and apart is reduced to sulfur dioxide, both of which are recovered from the condenser. Some of the SO2 wil l be dissolved in the water formed during the distillation while most of the SO2 will pass off as a gas. The acid distillate readily separates from the oily compound in the condenser. 'I'he oily compound is withdrawn separately and may be further purled, if necessary,-by neutralizing and washing with water. 'I'he neutralization may be desirable so as to remove any sulfur dioxide or acid which may be present, thereby preventing any corrosion in the gas lines or containers. The resulting nishedproduct which is the odorant is passed to storage. If desired, the volatile oil vapors may be condensed by means of a fractional condenser.

Although the desired odorant can be obtained by simple distillation of some sludges, it ispreferred, with most sludges, such as the sulfuric acid sludges, to first hydrolyze the sludge to produce a weak acid and a tar, the odorant being recovered from' the tar by distillation. 'Ihe usual method of-recovery is to add water to the sludge causing it to hydrolyze into weak sulfuric acid and an organic remainder sometimes called a tar. Some sludges are readily hydrolyzed at normal temperatures, whereas others require heating. Some (sludges require heating at temperatures above their boiling point, thus necessitating the use of pressure above atmospheric in order to reach the high hydrolyzing temperature. The acid and .tar separate into two layers and may be recovered separately. The upper or tar `layer contains the odorant.

If the tar from which the odorant is to be obtained has been produced by hydrolyzation of -sludge at normal temperatures, that is, without the application of heat to the hydrolyzing chamfrom each other.

ber, it is necessary to distill the tar and recover those fractions which are distilled off at temperatures up to about 600 F. andvwhichare condensable at atmospheric pressures. Any of the conventional distilling apparatus may be employed. A fractional condenser may be used to collect and separate any desired portion of the vapors.

If `the tar from which the odorant is to be obtained has been produced by steaming or heating in an open tank, a more volatile odorant will be produced. If it is desired to lower the volatility of the odorant this can be accomplished by distilling and fractionally condensing such por- .tions of the vapors as are desired for the odorant.

If the tar from which the odorant is to be obtained has been produced by hydrolysis at high temperatures and super-atmospheric pressures, the volatile fractions of the tar can be obtained by passing the tar from the sludge digester, through` a pressure regulating valve, into an evaporating chamber. The volatile portions of the tar containing the odorant may be vaporized by the residual heat in the tar and may be withdrawn from the chamber and condensed. Inasmuch as the volatile tar vapors from the evaporator are usually accompanied by some sulfur dioxide vapors it is desirable to separate them Since sulfur dioxide gas is readily soluble in water a separation can be obtained by passing all of the vapors from the vaporizing chamber through a body of water or through a scrubbing tower. One convenient condenser, using water as the condenser medium. The sulfur dioxide gas is dissolved in the water and the less volatile oil vapors are condensed.

'Ihe oil, vapors and water are passed through a separating chamber, the water being removed from the bottom, the i'lxed gases from the top, and the oil from the upper layer of liquid, above the water.

The oil which is obtained bythe method described above is the odorant which is the subject of the present invention. lThe oil from the separator may be neutralized as with caustic soda, if desired, washed with water, and passed to storage. By the termstemperature and pressure hydrolysis" and temperature and pressure distillation, reference is made to products produced by the distillation of sludge (or of sludge tars resulting `from hydrolysis of sludge) in which the sludge and tar are subjected to the action of superatmospheric pressure and temperature, thereby distinguishing from processes in which hydrolysis is accomplished by neutralization of sludge with `an alkali and other products derived from those processes. When alkali neutralization of sludge is employed, the product does not contain mercaptans which materially enhance the utility of the product for the purposes of this invention. In the attached' drawing the figure diagrammatically illustrates one arrangement of elements which may be used for the production of the odorant. It may include, for example, a continuous treater comprising an agitator I into which the sulfur-bearing petroleum oil is fed by line 2 and the acid by line 3'. The mixture is then discharged into the settling tank I, the treated petroleum oil being withdrawn through the line 5 whereas the sludge is discharged by the line -6 into a suitable still or hydrolyzer. An atmospheric pressure type hydrolyzer is illustrated at 1, water and steam being supplied thereto by lines 8 and 9 respectively. A separation into an upper tar or oil layer and a lower aqueous acid layer takes place, the odorant being then passed fby line I0 into a fractionating tower II from I9 respectively, the spent washing solution being discharged at 20. The washed odorant may then pass into a still 2| by means of a line 22, the odorant being fractionated at 23 and sent to storage by line 24. i

The odorant described hereinabove may be employed in any desired manner. For example, it may be introduced into the fuel gas in the form of a spray, although preferably the gas is passed through a tower or other porous bed-of material exposing a large surface area over which the odorant is sprayed or held by the absorption of the material with which the tower is packed. In view of the relatively small quantities of odorant necessary to impart a distinctive odor to the gas, the4 latter method, namely, addition to a column containing rocks, brick or tile, is preferred as more accurate control may be thus maintained over the quantity of odorant added tb the gas. One form of odorizer is illustrated in Fig. 2. As there shown, the combustible fuel gas flowing through the line 26 may be discharged into enlarged sections 21 containing series of spaced wicks held in suitable cages and indicated at 28. These wicks 28 may be fed with odorant supplied from a `supply tank 29 connected as by conduits 30 with the bottom portions of the wicks. The

fuel gas admitted by\ line 26 passes over and between the wicks, which become thoroughly wetted with the odorant by reason of their capillary action. The odorized gas is then discharged by the line 3I.

We claim:

1. A gaseous hydrocarbon fuel having a distinctive and penetrating odor and incapable of producing skin irritation, lachrymation or other undesirable physiological action, said gas fuel beingV substantially odorless when burned and containing about three gallons per million cubic feet of gas of a volatilized organic oil soluble product having a boiling point range of between F. and 600 F., said product being substantially free of sulfur dioxide and containing organic -.cycl.ic sulfides, the effective odorlzing constituents of said oil soluble product comprising principally organic cyclic suliides of the saturated ring heterocyclic type containing three or more carbon atoms and sulfur as a hetero-atom.

' 2. A gaseous hydrocarbon fuel of the character described, having a distinctive and penetrating odor, said gaseous fuel containing a vola- -tilized organic, sulfur-containing oil resulting from temperature and pressure hydrolysis and distillation of acid sludge formed during sulfuric acid treatment of petroleum oils, said volatilized i oil containing organic suldes, the effective odorizing constituents of the oil comprising prini. fuel having no marked vinherent odor, containing c'ipally organic suldes of the saturated ring heterocyclic type containing three or more carbonatoms and' sulfur as a hetero-atom.

3. A gaseous hydrocarbonl fuel of the character described, having a distinctive and penetrating odor,v said gaseous fuel containing a volatilized oil resulting from temperature and pressure hydrolysis and distillation of acid sludge formed during sulfuric acid treatment of petroleum oils, said oil having a boiling point range of between 100 F. and 600 F. and a sulfur content of from 2% to 18%, said volatilized oil containing organic sulfldes, the-effective odorizi ing constituents of the oil comprising principally organic suldes of the saturated ring heterocyclic type containing three or more carbon atoms and sulfur as' a hetero-atom.

4. A gaseous hydrocarbon fuel of the character described, having a distinctive and penetrating odor, said gaseous fuel containing a` volatilizedv oil resulting from temperature .and pressure hydrolysis and distillation of acid sludge formed during sulfuric acid treatment of petroleuml oils, having a .distillationz end point not above about 420 F. and a sulfur content of from 2% to 18%, said volatilized oil containing organic suldes, the Veffective odorizing constituents f..

the oil comprising principally organic suliides of the saturated ring heterocyclic type containing three`or more carbon atoms and sulfur as a hetero-atom.L

5. A gaseous hydrocarbon fuel of the character described, having a distinctive and penetrating odor, said gaseous fuel containing a volatilized oil having a sulfur content of above 2%,

producing skin irritation, lachrymation or otherundesirable physiological action, said gaseous fuel being substantallyodorless when burned, said gaseous fuel containing more than 0.25 part per million of a volatilized organic oil-soluble,y temperature and pressure distillation product of acid sludgeformed during treatment of petroleum oils with sulfuric acid for the removal of sulfur bodies from such petroleum oils, said distillation product being. substantially free from sulfur dioxide and containing over.v 2% total sulfur, said oil soluble product containing organic s ulfldes, the effective odorizing constituents of said product comprising principally organic sulfldes of the saturated ring heterocyclic type containingfthree or more carbon atoms and sul- 60 fur as a hetero-atom.

7. A gaseous fuel capable of being handled in a normal manner without deleterious effects, comprising; a gaseous combustible hydrocarbon a volatilized oil having a distillation/range of between 100 F. and 600 F.; said oil having a total sulfur content of above 2% and containing organic sulfldes of thecyclic sulde type; said oil being a; distillation product` of acid` sludge formedduring treatment of sulfur bearing mineraloil with sulfuric acid for the removal of sulfur bodies; ,said oil havinga penetrating- 'a normal manner. without deleterious eects.`

signal odor readily discernible in concentrations of about 0.25 part and'more per million; said gaseous fuel containing said oil in quantitiessu'l-l cient to impart a distinctive and penetrating odor thereto but being substantially odorless when burned,` the effective odorizing constituents .of the oil comprising principally organic cyclic sulfides of the saturated ring heterocyclic type containing three or more carbon atoms and sulfur as a hetero-atom.

` 8. A gaseous fuel capable of being handled in a normal manner without Vdeleterious effects, comprising: a gaseous combustible hydrocarbon fuel having no marked inherent odor, containing a .volatilized oil having a distillationrange of between 100 F. and 420 F. and yielding not less than 70% by distillation at.340'F.; said oil 'having a total sulfur content of above 2% and containing organic sulfides o'f the cyclic sulfide type; said oil being a distillation. product of heterocyclic type containing three or more carbon atoms and sulfur asa hetero-atom.

9. A gaseous fuel capable of being handled in a normal manner without deleterous effects comprising; a gaseous hydrocarbon fuel concontaining organic suldes of' the cyclic sulfide type; said oil being a distillation product of acid sludge formed during treatment of sulfur bearing mineral oilwitl i sulfur'icacid for the removal of sulfur bodies; .s'aid oil having a penetrating signal odor vreadily discernible in concentrations of about'0.25 part and moreper penetrating odorthereto but being substantially odorless when burned,l the effective odorizingconstituents of the.- oil .comprising principally organic cyclic suliidesof the saturated ring heterocyclic type vcontaining" three or more carbon atomsand sulfur asa hetero-atom.

10. A gaseous -.fuel capable offbeing handled iu a normal manner without deleterious effects,

` comprising: a. gaseous hydrocarbon fuel containing a volatilized -oil h ving a distillation range of between 100F. and 00 F.; said oil'having a total sulfur-content of between 2% and 18% and containing organic suldes of the cyclic' sulfide type; said oil being a distillation product of acid sludge formed during treatment of sulfur bearing mineral oil with sulfuric acid for the removal of sulfur bodies; said oil having a penetrating signal odor readily discernible in concentrations of about 0.25 part and more per million; said gaseous fuel containing saidoil in 4quantities su'icient to iming principally organic ycyclic Vsulde's of the sat- -urated ring heterocyclicitype containing'three or more carbon atoms and sulfur as a hetero-atom.

` -11. f A gaseous` fuel capable of being handled in I comprising: agaseous hydrocarbon fuel containties suilicient to impart a distinctiveand penetrating odor thereto but being substantially odorless when burned, the effective odorizing constituents of the oil comprising principally organic cyclic sulfides of the saturated ring heterocyclic type containing three or more carbon atomsand sulfur as a hetero-atom. x

12. A gaseous fuelcapable of being handled in aV normal manner without deleterious eiects, comprising: a gaseous hydrocarbon fuel containing a volatilized oil having a distillation range of between 100 F. and 600 F.; said oil having a total sulfur content of above.2% and containing organic suldes of the cyclic sulde type but being substantially free from sulfur dioxide; said oil being a distillation product of acid sludge formed during treatment of sulfur bearing min-l eral oil with sulfuric acid for the removal of sulfur bodies; said oil having a' penetrating signal odor readily' discernible in concentrations of about 0.25 part and more per million; said gaseous fuel containing said oil in .quantities suflicient to impart .-a distinctive and penetrating odor .thereto but being substantially odorless when burned, the effective odorizing constituents of the oil comprising principally'organic cyclic suldes of the saturated ring heterocyclic type containing three or more carbon atoms and sulfur as a.

hetero-atom. K

13.A gaseous fuel capable of being handled in a normal manner without -deleterious effects, comprising: a gaseous hydrocarbon fuel containlng a volatilized oil having a distillation range of between 100 F. and 420 F. and yielding not less than '70% by distillation at 340 F.; said oil having a total sulfur content of between 2% and 18% and containing organic sulfides ofthe cyclic sulde type but .beingsubstantially free from sulfur dioxide; said oil being adistillation product of acid sludge formed during treatment of sulfur bearing mineral oil with sulfuric acid for the removal of sulfur bodies; said oil having a penetrating signal odor readily discernible in concentrations of about 0.25lpart and more per million; said gaseous fuel containing said oil in quantities sumcient to impart a distinctive and pene- 'f trating odor thereto but being substantially odorless when burned, the effective odorizing constituents of the oil comprising principally organic cyclic suldes of thefsaturated ring heterocyclic type containing three or more carbon atoms and sulfur as a hetero-atom.

' 14. A gaseous fuel capable of being handled in a normal manner without deleterious effects, comprising: a gaseous hydrocarbon fuel containing a volatilized oil having a distillation range of between 100 F. and 420 F., said oil having a total sulfur content of between 2% and 18% and containing organic suldes of the cyclic sulde :type but being substantially free from sulfur dioxide, said oil being a product of hydrolysis and distillation of acid sludge formed during treat-x mentof sulfur bearing mineral oil with sulfuric acid for the removal of sulfur bodies; said oil having a penetrating signal odor readily discernible in concentrations of about,0.25 part and more per million; said gaseous fuel containing said oil in quantities sufcient to impart a distinctive an'd penetrating odor thereto but being substantially odorless when burned, the effective odorizing constituents of the oil comprising principally organic cyclic suldes ofthe saturated ring hetL erocyclic type containing three or more carbon atoms and sulfur as a hetero-atom.

15. A gaseous fuel capable of being handled in a normal manner without deleterious effects, comprising: a gaseous hydrocarbon fuel containing a volatilizedoil having a distillation range of between 100 F. and 600 F., said oil having a total sulfur` content of between 2% ,and 18% and containing organic suldes of the cyclic sulde type but being substantially free from sulfur dioxide,

said oil being a product of hydrolysis and distillation of acid sludge formed during treatment of sulfur bearing mineral oil with sulfuric acidv for the removal of sulfur bodies; said oil having a penetrating signal odor readily discernible in concentrations. of about 0.25 partand more per million; said gaseous fuel containing said oil in quantities .sumcient to impart a distinctive and penetrating odor thereto but being' substantially odorless when burned, the effective odorizing constituents ofthe oil comprising principally organic cyclic sulfides of the saturated ring-heterocyclic type containing three or more carbon atoms and sulfur as a hetero-atom.

16. In a method of producing a heating and `i11uminatmg gas having a. distinctive signal odor but being substantially odorless when hurried, the steps of: vaporizingian oil containing organic cyclic suldes of the saturated ring heterocyclic type containing three or more carbon atoms and sulfur as a hetero-atom in the gaseous fuel in quantities suilcient to impart a distinctive signal odor to said gas, said odor being distinguishable from the odor of common mercaptans, said oil having a distillation range of between 100 F. and 600 F., a total sulfur content of more than 2%, and being substantially free fromv sulfur dioxide, the eiective `odorizing constituents of the oil comprising principally the said organic cyclic suldes.

WILLIAM H. HAMPTON. JOHN T. RUTHERFORD.

CERTIFICATE oF CORRECTION.

Patent No. 2,064,805. December, 15, I193e WILLIAM H. HAMP T0N, ET AL.

It is hereby .certified that error appears in the prntedf specification of the above numbered patent requiring correction as follows: Page 1, first column, -line 20, -for the word "color"- readA odor; page 3, first column, line 67, for "the figure" read Fig. 1; and that the -said Letters Patent should' be read with th'fese corrections therein that the same may conform to therecord of the .oase :in the Patent Office. l A v .Signed and sealedthis 16th day of- Maroh,' A. D. 1937. f r

Heny Van Asd'ale (Seal) Acting (.yorvnmissionex of Patents.r 

